Systems and methods for sensor platform

ABSTRACT

Apparatus are provided for a sensor platform. The sensor platform includes a sensor mount adapted to receive a sensing device, and a first articulation system that has a first rotational axis. The sensor platform includes a second articulation system that has a second rotational axis, and the second rotational axis is different than the first rotational axis. The sensor platform includes a base that supports the first articulation system, the second articulation system and the sensor mount. The first articulation system and the second articulation system are independently movable to define two degrees of freedom for positioning the sensor platform.

TECHNICAL FIELD

The present disclosure generally relates to sensor systems, and moreparticularly relates to systems and methods that provide two degrees offreedom in a sensor platform for use in an autonomous vehicle.

BACKGROUND

An autonomous vehicle is a vehicle that is capable of sensing itsenvironment and navigating with little or no user input. An autonomousvehicle senses its environment using sensing devices such as radar,lidar, image sensors, and the like. The autonomous vehicle systemfurther uses information from global positioning systems (GPS)technology, navigation systems, vehicle-to-vehicle communication,vehicle-to-infrastructure technology and/or drive-by-wire systems tonavigate the vehicle.

Certain sensing devices are mounted to the autonomous vehicle by aplatform that enables the sensing device to move relative to theautonomous vehicle to provide a greater field of view for the sensingdevice. In these instances, in order to achieve a desired range ofmotion for the sensing device, a structure of the platform is cumbersomeand portions of the structure may obstruct the field of view of thesensing device. Moreover, an accuracy of the sensing device may dependupon an accuracy of a position of the sensing device relative to theautonomous vehicle. In certain instances, the accuracy of the positionmay be compromised due to backlash within the platform.

Accordingly, it is desirable to provide a platform for a sensing deviceof an autonomous vehicle, which enables the sensing device to moverelative to the autonomous vehicle without obstructing the field of viewof the sensor. It is also desirable to provide a platform for thesensing device that provides an absolute position of the sensing deviceby minimizing or eliminating backlash within the platform. Furthermore,other desirable features and characteristics of the present inventionwill become apparent from the subsequent detailed description and theappended claims, taken in conjunction with the accompanying drawings andthe foregoing technical field and background.

SUMMARY

In one embodiment, the sensor platform includes a sensor mount adaptedto receive a sensing device, and a first articulation system that has afirst rotational axis. The sensor platform includes a secondarticulation system that has a second rotational axis, and the secondrotational axis is different than the first rotational axis. The sensorplatform includes a base that supports the first articulation system,the second articulation system and the sensor mount. The firstarticulation system and the second articulation system are independentlymovable to define two degrees of freedom for positioning the sensorplatform.

In one embodiment, a sensor platform includes a first articulationsystem that has a first rotational axis. The sensor platform includes asecond articulation system that has a second rotational axis. The firstrotational axis is angularly offset from the second rotational axis. Thefirst articulation system is coupled to the second articulation systemsuch that the first articulation system and the second articulationsystem extend along a longitudinal axis. The first articulation systemand the second articulation system are independently movable to definetwo degrees of rotational freedom for positioning the sensor platform.

DESCRIPTION OF THE DRAWINGS

The exemplary embodiments will hereinafter be described in conjunctionwith the following drawing figures, wherein like numerals denote likeelements, and wherein:

FIG. 1A is a perspective view of a vehicle having a sensor platform fora sensing device, in accordance with various embodiments;

FIG. 1B is a functional block diagram illustrating an autonomous vehiclehaving a sensor platform, in accordance with various embodiments;

FIG. 1C is a functional block diagram illustrating a transportationsystem having one or more autonomous vehicles of FIG. 1B, in accordancewith various embodiments;

FIG. 2 is a perspective view of the sensor platform of FIG. 1A, whichillustrates a first articulated position for the sensor platform, inaccordance with various embodiments;

FIG. 3 is an exploded view of the sensor platform, in accordance withvarious embodiments;

FIG. 4 is a perspective view of a first articulation body, whichincludes a bearing, of the sensor platform of FIG. 2, in accordance withvarious embodiments;

FIG. 5 is a side view of the sensor platform of FIG. 2, whichillustrates a second or non-articulated position for the sensorplatform, in accordance with various embodiments;

FIG. 6 is a cross-sectional view of the sensor platform of FIG. 2, takenalong line 6-6 of FIG. 2, in accordance with various embodiments;

FIG. 7 is a perspective view of a second articulation body, whichincludes a bearing, of the sensor platform of FIG. 2, in accordance withvarious embodiments;

FIG. 8 is a perspective view of a body of a base of the sensor platformof FIG. 2, which includes a bearing, in accordance with variousembodiments;

FIG. 9 is a dataflow diagram illustrating a control system of the sensorplatform of FIG. 2, in accordance with various embodiments;

FIG. 10 is side view of the sensor platform of FIG. 2, which illustratesa portion of a spherical coordinate system for the sensor platform, withthe sensor platform in a neutral position, in accordance with variousembodiments;

FIG. 11 is a flowchart illustrating a control method for controlling thesensor platform of FIG. 2, in accordance with various embodiments;

FIG. 12 is a perspective view of another sensor platform for use withthe vehicle of FIG. 1A, which illustrates a first articulated positionfor the sensor platform, in accordance with various embodiments; and

FIG. 13 is a cross-sectional view of the sensor platform of FIG. 12,taken along line 13-13 of FIG. 12, in accordance with variousembodiments.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the application and uses. Furthermore, there is nointention to be bound by any expressed or implied theory presented inthe preceding technical field, background, brief summary or thefollowing detailed description. As used herein, the term module refersto any hardware, software, firmware, electronic control component,processing logic, and/or processor device, individually or in anycombination, including without limitation: application specificintegrated circuit (ASIC), an electronic circuit, a processor (shared,dedicated, or group) and memory that executes one or more software orfirmware programs, a combinational logic circuit, and/or other suitablecomponents that provide the described functionality.

Embodiments of the present disclosure may be described herein in termsof functional and/or logical block components and various processingsteps. It should be appreciated that such block components may berealized by any number of hardware, software, and/or firmware componentsconfigured to perform the specified functions. For example, anembodiment of the present disclosure may employ various integratedcircuit components, e.g., memory elements, digital signal processingelements, logic elements, look-up tables, or the like, which may carryout a variety of functions under the control of one or moremicroprocessors or other control devices. In addition, those skilled inthe art will appreciate that embodiments of the present disclosure maybe practiced in conjunction with any number of systems, and that thesensor platform system described herein is merely one exemplaryembodiment of the present disclosure.

For the sake of brevity, conventional techniques related to signalprocessing, data transmission, signaling, control, and other functionalaspects of the systems (and the individual operating components of thesystems) may not be described in detail herein. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent example functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in an embodiment of the present disclosure.

As used herein, the term “axial” refers to a direction that is generallyparallel to or coincident with an axis of rotation, axis of symmetry, orcenterline of a component or components. For example, in a cylinder ordisc with a centerline and generally circular ends or opposing faces,the “axial” direction may refer to the direction that generally extendsin parallel to the centerline between the opposite ends or faces. Incertain instances, the term “axial” may be utilized with respect tocomponents that are not cylindrical (or otherwise radially symmetric).For example, the “axial” direction for a rectangular housing containinga rotating shaft may be viewed as a direction that is generally parallelto or coincident with the rotational axis of the shaft. Furthermore, theterm “radially” as used herein may refer to a direction or arelationship of components with respect to a line extending outward froma shared centerline, axis, or similar reference, for example in a planeof a cylinder or disc that is perpendicular to the centerline or axis.In certain instances, components may be viewed as “radially” alignedeven though one or both of the components may not be cylindrical (orotherwise radially symmetric). Furthermore, the terms “axial” and“radial” (and any derivatives) may encompass directional relationshipsthat are other than precisely aligned with (e.g., oblique to) the trueaxial and radial dimensions, provided the relationship is predominatelyin the respective nominal axial or radial direction. As used herein, theterm “transverse” denotes an axis that crosses another axis at an anglesuch that the axis and the other axis are neither substantiallyperpendicular nor substantially parallel.

With reference to FIG. 1A, a sensor platform system shown generally at100 is associated with a vehicle 10 in accordance with variousembodiments. The sensor platform system 100 movably couples at least onesensing device 102 to the vehicle 10. FIG. 1A illustrates the vehicle 10as having two sensor platform systems 100, each with a respective one oftwo sensing devices 102 that operate in a same or similar manner. Forease of the description, only one of the sensor platform systems 100 andthe sensing devices 102 will be described herein.

Generally, the sensor platform system 100 couples the sensing device 102to the vehicle 10 such that the sensor platform system 100 is movablewith two rotational degrees of freedom, which may enable the sensingdevice 102 to be movable with three rotational degrees of freedom.Generally, the sensor platform system 100 is stationary in yaw (e.g.,stationary in rotation about the Z-axis) with respect to the vehicle 10and movable in pitch (e.g., rotation about the Y-axis) and roll (e.g.,rotation about the X-axis). In certain embodiments, the sensing device102 is movable in yaw (e.g., rotation about the Z-axis), pitch (e.g.,rotation about the Y-axis), and roll (e.g., rotation about the X-axis).In various embodiments, the sensor platform system 100 controls amovement of the sensing device 102 based on control signals receivedfrom at least one control module 18 (FIG. 1B). Although the figuresshown herein depict an example with certain arrangements of elements,additional intervening elements, devices, features, or components may bepresent in an actual embodiment. It should also be understood that FIG.1A is merely illustrative and may not be drawn to scale. Although thesensor platform system 100 is shown to be associated with an automobilein FIG. 1A, it should be noted that the sensor platform system 100 canbe used with any suitable vehicle, such as an aircraft, ship, train,motorcycle, scooter, etc. Moreover, the sensor platform system 100 canbe used in one or more non-vehicular or stationary applications.

In various embodiments, the vehicle 10 is an autonomous vehicle. Anautonomous vehicle is, for example, a driverless vehicle that isautomatically controlled to carry passengers from one location toanother. FIG. 1B illustrates exemplary components that may beimplemented in the vehicle 10 to achieve the automatic control of thevehicle 10. For example, components may include: a sensor system 12, anactuator system 14, a data storage device 16, and the at least onecontrol module 18. The sensor system 12 includes one or more sensingdevices 102 a-102 n that sense observable conditions of the exteriorenvironment and/or interior environment of the vehicle 10. The sensingdevices 102 a-102 n can include, but are not limited to, radars, lidars,and cameras. In various embodiments, the sensor system 12 includes thesensor platform system 100 that is associated with the sensing devices102 a-102 n as described herein.

The actuator system 14 includes one or more actuator devices 14 a-14 nthat control one or more vehicle components. In various embodiments, thevehicle components are associated vehicle operation and can include, butare not limited to, a throttle, brakes, and a steering system. Invarious embodiments, the vehicle components are associated with interiorand/or exterior vehicle features and can include, but are not limitedto, doors, a trunk, and cabin features such as air, music, lighting,etc.

The data storage device 16 stores data for use in automaticallycontrolling the vehicle 10. In various embodiments, the data storagedevice 16 stores defined maps of the navigable environment. In variousembodiments, the defined maps may be predefined by and obtained from aremote system 20. For example, the defined maps may be assembled by theremote system 20 and communicated to the vehicle 10 (wirelessly and/orin a wired manner) and stored by the control module 18 in the datastorage device 16. As can be appreciated, the data storage device 16 maybe part of the control module 18, separate from the control module 18,or part of the control module 18 and part of a separate system.

The control module 18 includes at least one processor 22 and memory 24.The processor 22 can be any custom made or commercially availableprocessor, a central processing unit (CPU), an auxiliary processor amongseveral processors associated with the control module 18, asemiconductor based microprocessor (in the form of a microchip or chipset), a macroprocessor, or generally any device for executinginstructions. The memory 24 may be one or a combination of storageelements that store data and/or instructions that can be performed bythe processor 22. The instructions may include one or more separateprograms, each of which comprises an ordered listing of executableinstructions for implementing logical functions.

The instructions, when executed by the processor 22, receive and processsignals from the sensor system 12, perform logic, calculations, methodsand/or algorithms for automatically controlling the components of thevehicle 10, and generate control signals to the actuator system 14 toautomatically control the components of the vehicle 10 based on thelogic, calculations, methods, and/or algorithms. Although only onecontrol module 18 is shown in FIG. 1B, embodiments of the vehicle 10 caninclude any number of control modules 18 that communicate over anysuitable communication medium or a combination of communication mediumsand that cooperate to process the sensor signals, perform logic,calculations, methods, and/or algorithms, and generate control signalsto automatically control features of the vehicle 10. In variousembodiments, the instructions, when executed by the processor 22,control operation of the sensor platform system 100 as will be describedin more detail below.

In various embodiments, the autonomous vehicle described with regard toFIG. 1B may be suitable for use in the context of a taxi or shuttlesystem in a certain geographical area (e.g., a city, a school orbusiness campus, a shopping center, an amusement park, an event center,or the like). For example, the autonomous vehicle 10 may be associatedwith an autonomous vehicle based transportation system. FIG. 1Cillustrates an exemplary embodiment of an operating environment showngenerally at 26 that includes an autonomous vehicle based transportationsystem 28 that is associated with one or more autonomous vehicles 10a-10 n as described with regard to FIG. 1B. In various embodiments, theoperating environment 26 includes the transportation system 28, at leastone user device 30, and a communication network 32.

The communication network 32 supports communication as needed betweendevices, systems, and components supported by the operating environment26 (e.g., via tangible communication links and/or wireless communicationlinks). Although only one user device 30 is shown in FIG. 1C,embodiments of the operating environment 26 can support any number ofuser devices 30, including multiple user devices 30 owned, operated, orotherwise used by one person. Each user device 30 supported by theoperating environment 26 may be implemented using any suitable hardwareplatform. In this regard, the user device 30 can be realized in anycommon form factor including, but not limited to: a desktop computer; amobile computer (e.g., a tablet computer, a laptop computer, or anetbook computer); a smartphone; a video game device; a digital mediaplayer; a piece of home entertainment equipment; a digital camera orvideo camera; a wearable computing device (e.g., smart watch, smartglasses, smart clothing); or the like. Each user device 30 supported bythe operating environment 26 is realized as a computer-implemented orcomputer-based device having the hardware, software, firmware, and/orprocessing logic needed to carry out the various techniques andmethodologies described herein.

The autonomous vehicle based transportation system 28 includes one ormore backend server systems, which may be cloud-based, network-based, orresident at the particular campus or geographical location serviced bythe transportation system 28. The backend system can communicate withthe user devices 30 and the autonomous vehicles 10 a-10 n to schedulerides, dispatch autonomous vehicles 10 a-10 n, and the like.

In accordance with a typical use case workflow, a registered user of thetransportation system 28 can create a ride request via the user device30. The ride request will typically indicate the passenger's desiredpickup location (or current GPS location), the desired destinationlocation (which may identify a predefined vehicle stop and/or auser-specified passenger destination), and a pickup time. Thetransportation system 28 receives the ride request, processes therequest, and dispatches a selected one of the autonomous vehicles 10a-10 n (when and if one is available) to pick up the passenger at thedesignated pickup location and at the appropriate time. Thetransportation system 28 can also generate and send a suitablyconfigured confirmation message or notification to the user device 30,to let the passenger know that a vehicle is on the way.

As can be appreciated, the subject matter disclosed herein providescertain enhanced features and functionality to what may be considered asa standard or baseline autonomous vehicle and/or autonomous vehiclebased transportation system 28. To this end, an autonomous vehicle andautonomous vehicle based transportation system can be modified,enhanced, or otherwise supplemented to provide the additional featuresdescribed in more detail below.

With reference now to FIG. 2, the sensor platform system 100 will bedescribed in more detail in accordance with various embodiments. Invarious embodiments, the sensor platform system 100 includes a sensormount 108, a first articulation system 110, a second articulation system112 and a base system 114. Generally, the sensor platform system 100extends along a longitudinal axis L, with each of the first articulationsystem 110 and the second articulation system 112 extending along andmovable relative to the longitudinal axis L. In one example, the firstarticulation system 110 and the second articulation system 112 are eachindependently rotatable relative to the longitudinal axis L.

The sensor mount 108 is coupled to the sensing device 102. In thisexample, with reference to FIG. 3, the sensor mount 108 is annular, andincludes a first surface 120 opposite a second surface 122. The sensormount 108 is generally composed of a metal or metal alloy, including,but not limited to aluminum; however, it will be understood that thesensor mount 108 may also be composed of any suitable polymericmaterial. The sensor mount 108 can be formed through any suitabletechnique, such as casting, molding, stamping, forging, selective lasersintering, etc. The first surface 120 is coupled to the sensing device102. In one example, a bore 124 is defined through the first surface120, which receives a mechanical fastener, including, but not limited toa screw, bolt, rivet, etc., to removably couple the sensing device 102to the sensor mount 108. The second surface 122 is coupled to the firstarticulation system 110. Generally, the sensor mount 108 includes aplurality of recesses 126 defined through the first surface 120 and thesecond surface 122 about a perimeter of the sensor mount 108. Theplurality of recesses 126 cooperate with and receive a portion of thefirst articulation system 110 to couple the first articulation system110 to the sensor mount 108 such that a portion of the firstarticulation system 110 is received within the plurality of recesses 126(FIG. 3).

The first articulation system 110 includes an interface 130, a bearing132, a first articulation body or cylinder 134 and a first drive system136. The interface 130 is annular, and is coupled to the sensor mount108. The interface 130 is generally composed of metal or metal alloy,and in one example, is composed of aluminum. However, it will beunderstood that the interface 130 may be composed of any suitablepolymeric material. The interface 130 can be formed through any suitabletechnique, such as, but not limited to, casting, molding, stamping,forging, selective laser sintering, etc. The interface 130 includes afirst side 140 opposite a second side 142. The first side 140 includes aplurality of projections 144, which extend outwardly from the first side140, in a direction substantially parallel with the longitudinal axis L.Each of the plurality of projections 144 are received within arespective one of the plurality of recesses 126 to couple the interface130 to the sensor mount 108. In this example, one or more of theplurality of projections 144 define a bore 146, which cooperates withcorresponding bores 148 defined in corresponding ones of the pluralityof recesses 126 to receive a mechanical fastener, including, but notlimited to a screw, bolt, etc., to couple the interface 130 to thesensor mount 108.

The second side 142 of the interface 130 has a diameter that isdifferent than, and in this example, less than a diameter of the firstside 140. Generally, the diameter of the second side 142 is differentthan the diameter of the first side 140 to form a seat for the bearing132. The second side 142 also includes a joint 150. The joint 150generally extends from the second side 142 along a central axis definedthrough the interface 130. The joint 150 includes a first post 152 and asecond post 154, which are interconnected at a universal joint 156. Thefirst post 152 is fixedly coupled to the second side 142, and the secondpost 154 is coupled to a flexible drive shaft 160 of the base system114. The first post 152 is coupled to the second side 142 via anytechnique, such as, but not limited to, bonding, welding, mechanicalfasteners, and can be integrally formed with the interface 130, ifdesired. As will be discussed further herein, the universal joint 156cooperates with the flexible drive shaft 160 to fix the sensor mount 108in yaw (Z-axis) with respect to the base system 114. In other words, theuniversal joint 156 enables the sensor mount 108 to roll (X-axis) andpitch (Y-axis) relative to the base system 114, while remainingstationary in yaw (Z-axis).

The bearing 132 seats about a circumference of the second side 142 ofthe interface 130 and is substantially cylindrical. In this example, thebearing 132 is a thrust bearing, including, but not limited to, a thrustball bearing, a thrust roller bearing, etc. The bearing 132 facilitatesthe rotation of the first articulation cylinder 134 relative to thesecond articulation system 112, and supports axial loads generated fromthis relative rotation. The bearing 132 includes an inner ring 132 a andan outer ring 132 b. The inner ring 132 a is coupled to the second side142 of the interface 130, and the outer ring 132 b is coupled to thefirst articulation cylinder 134.

The first articulation cylinder 134 includes a first surface 170opposite a second surface 172 and a first throughbore 174. Withreference to FIG. 4, the first articulation cylinder 134 issubstantially cylindrical, and may be substantially hollow. It should benoted that while the first articulation cylinder 134 is described andillustrated herein as having a cylindrical shape, the first articulationcylinder 134 need not be cylindrical, but may be any suitable shape. Thefirst articulation cylinder 134 is composed of metal or metal alloy, andin one example, is composed of aluminum. However, it will be understoodthe first articulation cylinder 134 may be composed of any suitablepolymeric material. The first articulation cylinder 134 can be formedthrough any suitable technique, such as, but not limited to, casting,molding, stamping, forging, selective laser sintering, etc. The firstsurface 170 defines a counterbore 176, which receives the outer ring 132b of the bearing 132.

Generally, with reference to FIG. 5, the first surface 170 is planar andthe second surface 172 is sloped or slanted to define a wedge-shapedelement. As such, a first end 135 of the first articulation cylinder 134has a length along the longitudinal axis L, which is less than a lengthof a second end 137 of the first articulation cylinder 134 along thelongitudinal axis L. Stated another way, the first surface 170 extendsalong an axis A, which is substantially transverse or oblique to an axisA2 of the second surface 172. In other words, generally, the firstarticulation cylinder 134 has an axis of rotation R, and the firstsurface 170 has a radial axis that is substantially transverse oroblique to the axis of rotation R, while the second surface 172 has aradial axis that is substantially perpendicular to the axis of rotationR. Thus, the axis of rotation R of the first articulation cylinder 134is substantially perpendicular to the second surface 172, and thusangularly offset to the first surface 170. In one example, the slant ofthe second surface 172 is about 7.5 degrees. Generally, the slant of thesecond surface 172 is θ_(s), which defines a maximum value for phi (φ)that can be input to control a motion of the sensor platform system 100,as will be discussed in detail below.

With reference to FIG. 4, the second surface 172 also defines a secondcounterbore 178. The second counterbore 178 receives a portion of thefirst drive system 136 to drive the first articulation cylinder 134. Thesecond surface 172 also optionally defines a pin hole 179, whichreceives a dowel pin to assist in assembling the first articulationsystem 110.

The first throughbore 174 is defined through the first articulationcylinder 134 from the first surface 170 to the second surface 172. Thefirst throughbore 174 is sized to enable the rotation of the firstarticulation cylinder 134 relative to the joint 150 such that the firstarticulation cylinder 134 does not contact the joint 150.

With reference to FIG. 3, the first drive system 136 directly drives thefirst articulation cylinder 134. The first drive system 136 includes amotor 180, a spindle 182, a drive ring 184, a position sensor 186 and asecond, drive system bearing 188. In this example, with reference toFIG. 6, the motor 180, the spindle 182, the position sensor 186, thedrive system bearing 188 and a portion of the drive ring 184 arereceived within the second articulation system 112, such that the motor180, the spindle 182, the position sensor 186, the drive system bearing188 and a portion of the drive ring 184 are nested within the secondarticulation system 112. Thus, at least a portion of the first drivesystem 136 couples the first articulation system 110 to the secondarticulation system 112.

Generally, the motor 180 comprises a brushless direct current ringmotor. The motor 180 is in communication with the control module 18 overa communication architecture that facilitates the transfer of power,data, commands, control signals, etc. The spindle 182 is received thougha bore defined by a rotor 180 a of the motor 180, and is coupled to therotor 180 a to be driven by the rotation of the rotor 180 a. The spindle182 is coupled to the rotor 180 a via any suitable technique, including,but not limited to, adhesives, a splined coupling, welding, press-fit,etc. In one example, the spindle 182 is bonded, via an adhesive, to therotor 180 a. The spindle 182 is generally composed of a metal or metalalloy, including, but not limited to, aluminum. However, it will beunderstood the spindle 182 may be composed of any suitable polymericmaterial. The spindle 182 can be formed through any suitable technique,such as, but not limited to, casting, molding, stamping, forging,selective laser sintering, etc. The spindle 182 is generally cylindrical(FIG. 3), and has a first end 190 coupled to the position sensor 186 anda second end 192 coupled to the drive ring 184. The spindle 182 definesthe axis of rotation R for the first articulation cylinder 134.Generally, the motor 180 receives one or more control signals from thecontrol module 18, which causes the motor 180 to drive the spindle 182in the desired direction, such as clockwise or counterclockwise aboutthe axis of rotation R. As the spindle 182 is coupled to the drive ring184, which is coupled to the first articulation cylinder 134, therotation of the spindle 182 results in a corresponding movement of thefirst articulation cylinder 134. In one example, the first articulationcylinder 134 is movable about the axis of rotation R through about 360degrees.

The drive ring 184 includes a first, base portion 194 and a second,engagement portion 196. The drive ring 184 is composed of metal or metalalloy, and in one example, is composed of aluminum. However, it will beunderstood the drive ring 184 may be composed of any suitable polymericmaterial. The drive ring 184 can be formed through any suitabletechnique, such as, but not limited to, casting, molding, stamping,forging, selective laser sintering, etc. In this example, the baseportion 194 has a diameter that is different, and generally smallerthan, the engagement portion 196. The base portion 194 is coupled to thesecond end 192 of the spindle 182, and may include one or more sprocketsand a hub to assist in transferring load or torque from the spindle 182to the drive ring 184. The base portion 194 can be coupled to thespindle 182 via any technique, such as adhesive, press-fit, splinecoupling, welding, etc., and can be integrally formed with the spindle182. The diameter of the base portion 194 is generally sized to define aseat for the drive system bearing 188, as will be discussed furtherherein.

The engagement portion 196 extends outwardly from the base portion 194,and is coupled to the first articulation cylinder 134. The engagementportion 196 is annular (FIG. 3), and the diameter is sized to bereceived within the second counterbore 178 to couple the drive ring 184to the first articulation cylinder 134. In one example, the engagementportion 196 is bonded to the second counterbore 178 via an adhesive;however, the engagement portion 196 may be fixedly coupled to the secondcounterbore 178 via any technique, such as welding, press-fit, etc.Thus, the engagement portion 196 is not received or nested within thesecond articulation system 112.

The position sensor 186 observes the first end 190 of the spindle 182and generates sensor signals based thereon. The position sensor 186 isin communication with the control module 18 over a communicationarchitecture that facilitates the transfer of data, power, commands,control signals, etc. Generally, the position sensor 186 is an encoder,which generates sensor signals based on the observed position of thespindle 182. In one example, the position sensor 186 is an absoluterotary encoder, which observes an angular position or motion of thespindle 182 and generates sensor signals based thereon. As the positionsensor 186 is coupled or mounted directly on the spindle 182 and thespindle 182 directly drives the first articulation cylinder 134 via thedrive ring 184, direct feedback is provided to the control module 18 ofthe position of the spindle 182, and thus, the position of the firstarticulation cylinder 134, thereby increasing an accuracy of a positionof the sensor platform system 100.

The drive system bearing 188 seats about the base portion 194 of thedrive ring 184 and is substantially cylindrical (FIG. 3). In thisexample, the drive system bearing 188 is a thrust bearing, including,but not limited to, a thrust ball bearing, a thrust roller bearing, etc.The drive system bearing 188 facilitates the rotation of the firstarticulation cylinder 134 relative to the second articulation system112, and supports axial loads generated from this relative rotation. Thedrive system bearing 188 includes an inner ring 188 a and an outer ring188 b. The inner ring 188 a is coupled to the base portion 194 of thedrive ring 184, and the outer ring 188 b is coupled to the secondarticulation system 112.

The second articulation system 112 cooperates with the firstarticulation system 110 to move the sensing device 102 in the twodegrees of freedom. With reference to FIG. 3, the second articulationsystem 112 includes a second articulation body or cylinder 200 and asecond drive system 202. With reference to FIG. 7, the secondarticulation cylinder 200 includes a third surface 204 opposite a fourthsurface 206 and a second throughbore 208. The second articulationcylinder 200 is substantially cylindrical, and may be substantiallyhollow. It should be noted that while the second articulation cylinder200 is described and illustrated herein as having a cylindrical shape,the second articulation cylinder 200 need not be cylindrical, but may beany suitable shape. The second articulation cylinder 200 is generallycomposed of metal or metal alloy, and in one example, is composed ofaluminum. However, it will be understood the second articulationcylinder 200 may be composed of any suitable polymeric material. Thesecond articulation cylinder 200 can be formed through any suitabletechnique, such as, but not limited to, casting, molding, stamping,forging, selective laser sintering, etc. The third surface 204 defines athird counterbore 210, which receives the outer ring 188 b of the drivesystem bearing 188.

Generally, with reference to FIG. 5, the third surface 204 is sloped orslanted with respect to the fourth surface 206 and the fourth surface206 is planar to define a wedge-shaped element. As such, a first end 201of the second articulation cylinder 200 has a length along thelongitudinal axis L, which is greater than a length of a second end 203of the second articulation cylinder 200 along the longitudinal axis L.Stated another way, the third surface 204 extends along an axis A3,which is substantially transverse or oblique to an axis A4 of the fourthsurface 206. In other words, generally, the second articulation cylinder200 has an axis of rotation R3, and the third surface 204 has a radialaxis that is substantially perpendicular to the axis of rotation R3,while the fourth surface 206 has a radial axis that is substantiallytransverse or oblique to the axis of rotation R3. The axis of rotationR3 of the second articulation system 112 is substantially parallel tothe longitudinal axis L, while the axis of rotation R of the firstarticulation system 110 is substantially transverse or oblique to thelongitudinal axis L. Thus, the axis of rotation R3 of the secondarticulation cylinder 200 is substantially perpendicular to the thirdsurface 204 and thus angularly offset with respect to the fourth surface206. In one example, the slant of the third surface 204 with respect tothe fourth surface 206 is about 7.5 degrees. Generally, the slant of thethird surface 204 is equal to the slant of the second surface 172 toprovide for a neutral position, as illustrated in FIG. 10.

With reference back to FIG. 5, the slanted second surface 172 of thefirst articulation cylinder 134 and the slanted third surface 204 of thesecond articulation cylinder 200 cooperate to define between aboutpositive 15 degrees and about negative 15 degrees of motion for thesensing device 102 in pitch (Y-axis) and roll (X-axis) relative to thelongitudinal axis L due to the respective 7.5 degrees slant of thesecond surface 172 and the third surface 204. In this example, thelongitudinal axis L is substantially parallel to the Z-axis. Statedanother way, the first articulation system 110 and the secondarticulation system 112 are independently movable by the respective oneof the first drive system 136 and the second drive system 202 to definetwo degrees of rotational freedom for the sensor platform system 100.Generally, the axis of rotation R of the first articulation cylinder 134of the first articulation system 110 is different than, and in thisexample, is transverse or angularly offset with respect to the axis ofrotation R3 of the second articulation cylinder 200 of the secondarticulation system 112 such that a rotational vector defined by therotation of the first articulation cylinder 134 is different than arotational vector defined by the rotation of the second articulationcylinder 200. Thus, the sensor platform system 100 defines two differentrotational vectors, which result in the two degrees of freedom movementfor the sensing device 102 relative to the vehicle 10. Stated anotherway, the axis of rotation R of the first articulation cylinder 134 ofthe first articulation system 110 is different than, and in thisexample, is transverse or angularly offset with respect to the axis ofrotation R3 of the second articulation cylinder 200 of the secondarticulation system 112 such that a rotation of a unit vector V₁ (FIG.10) about the axis of rotation R3 and the axis of rotation R results inthe two degrees of freedom movement for the sensing device 102 relativeto the vehicle 10. In addition, it should be noted that anysubstantially equal combinations of slants for the second surface 172and the third surface 204 can be employed to result in a desired rangeof motion for the sensor platform system 100.

With reference to FIG. 6, the fourth surface 206 also defines a fourthcounterbore 212. The fourth counterbore 212 receives a portion of thesecond drive system 202 to drive the second articulation cylinder 200.The fourth surface 206 also optionally defines a pin hole, whichreceives a dowel pin to assist in assembling the second articulationsystem 112. The fourth surface 206 optionally defines a plurality ofbores, which receive one or more mechanical fasteners, such as bolts,screws, etc., to removably couple a portion of the second drive system202 to the second articulation cylinder 200. In this regard, the one ormore mechanical fasteners are removable for maintenance and inspectionof the first drive system 136 that is positioned within the secondarticulation cylinder 200.

The second throughbore 208 is defined through the second articulationcylinder 200 from the third surface 204 to the fourth surface 206. Thesecond throughbore 208 is sized to receive the first drive system 136and in one example, the second throughbore 208 includes an annularflange 214. The annular flange 214 defines a bore 216 that is coupled tothe motor 180 of the first drive system 136. The annular flange 214supports the motor 180, while enabling the second articulation cylinder200 to move relative to the first drive system 136. The annular flange214 can also include one or more bores, which can provide a masssavings. The second throughbore 208 also enables the flexible driveshaft 160 to pass through the second articulation cylinder 200 withoutcontacting the second articulation cylinder 200.

As the second drive system 202 can be similar to the first drive system136, the same reference numerals will be used to denote the same orsubstantially similar components. The second drive system 202 directlydrives the second articulation cylinder 200. The second drive system 202includes the motor 180, the spindle 182, the drive ring 184, theposition sensor 186 and the drive system bearing 188. In this example,the motor 180, the spindle 182, the position sensor 186, the drivesystem bearing 188 and a portion of the drive ring 184 are receivedwithin the base system 114, such that the motor 180, the spindle 182,the position sensor 186, the drive system bearing 188 and a portion ofthe drive ring 184 are nested within the base system 114.

The motor 180 of the second drive system 202 is in communication withthe control module 18 over a communication architecture that facilitatesthe transfer of power, data, commands, control signals, etc. The spindle182 is received though a bore defined by the rotor 180 a of the motor180, and is coupled to the rotor 180 a to be driven by the rotation ofthe rotor 180 a. The spindle 182 is generally cylindrical, and has thefirst end 190 coupled to the position sensor 186 and the second end 192coupled to the drive ring 184. The spindle 182 defines the axis ofrotation R3 for the second articulation cylinder 200. Generally, themotor 180 receives one or more control signals from the control module18, which causes the motor 180 to drive the spindle 182 in the desireddirection, such as clockwise or counterclockwise about the axis ofrotation R3. As the spindle 182 is coupled to the drive ring 184, whichis coupled to the second articulation cylinder 200, the movement of thespindle 182 results in a corresponding movement of the secondarticulation cylinder 200. In one example, the second articulationcylinder 200 is movable about the axis of rotation R3 through about 360degrees.

The drive ring 184 includes the first, base portion 194 and the second,engagement portion 196. The base portion 194 is coupled to the secondend 192 of the spindle 182, and may include one or more sprockets and ahub to assist in transferring load or torque from the spindle 182 to thedrive ring 184. The diameter of the base portion 194 is generally sizedto define a seat for the drive system bearing 188.

The engagement portion 196 extends outwardly from the base portion 194,and is coupled to the second articulation cylinder 200. The engagementportion 196 is annular (FIG. 3), and the diameter is sized to bereceived within the fourth counterbore 212 to couple the drive ring 184to the second articulation cylinder 200. In one example, the engagementportion 196 is bonded to the fourth counterbore 212 via an adhesive;however, the engagement portion 196 may be fixedly coupled to the fourthcounterbore 212 via any technique, such as welding, press-fit, etc.Optionally, the engagement portion 196 can include one or more boresthat cooperate with the one or more bores 216 of the fourth surface 206to receive the plurality of mechanical fasteners. Thus, the engagementportion 196 is not received or nested within the base system 114.

The position sensor 186 observes the first end 190 of the spindle 182and generates sensor signals based thereon. The position sensor 186 isin communication with the control module 18 over a communicationarchitecture that facilitates the transfer of data, power, commands,control signals, etc. As the position sensor 186 is coupled or mounteddirectly on the spindle 182 and the spindle 182 directly drives thesecond articulation cylinder 200 via the drive ring 184, direct feedbackis provided to the control module 18 of the position of the spindle 182,and thus, the position of the second articulation cylinder 200, therebyincreasing an accuracy of a position of the sensor platform system 100.

The drive system bearing 188 seats about the base portion 194 of thedrive ring 184 and is substantially cylindrical. The drive systembearing 188 facilitates the rotation of the second articulation cylinder200 relative to the first articulation system 110, and supports axialloads generated from this relative rotation. The drive system bearing188 includes the inner ring 188 a and the outer ring 188 b. The innerring 188 a is coupled to the base portion 194 of the drive ring 184, andthe outer ring 188 b is coupled to the base system 114.

The base system 114 receives the portion of the second drive system 202.The base system 114 supports the first articulation system 110, thesecond articulation system 112, the sensor mount 108 and the sensingdevice 102, and is coupled to the vehicle 10. With reference to FIG. 3,the base system 114 includes a body 220, the flexible drive shaft 160, ashaft coupling 222 and a base plate 224. With reference to FIG. 8, thebody 220 is generally cylindrical, and is composed of metal or metalalloy, and in one example, is composed of aluminum. However, it will beunderstood the body 220 may be composed of any suitable polymericmaterial. The body 220 can be formed through any suitable technique,such as, but not limited to, casting, molding, stamping, forging,selective laser sintering, etc. The body 220 defines a fifth surface230, a sixth surface 232 and a throughbore 234 that extends through thebody 220 along the longitudinal axis L. With reference to FIG. 6, thefifth surface 230 defines a fifth counterbore 236, which receives theouter ring 188 b of the drive system bearing 188 and the base portion194 of the second drive system 202 to enable the drive ring 184 torotate relative to the base system 114.

The sixth surface 232 of the body 220 defines one or more bores about aperimeter of the sixth surface 232 for receipt of one or more mechanicalfasteners, such as screws, bolts, etc., to removably couple the body 220to the base plate 224. The mechanical coupling between the body 220 andthe base plate 224 facilitates maintenance and inspection of the seconddrive system 202.

The throughbore 234 extends through the body 220 from the fifth surface230 to the sixth surface 232. The throughbore 234 is sized to receivethe portion of the second drive system 202 and in one example, thethroughbore 234 includes an annular flange 238. The annular flange 238defines a bore 239 that is coupled to the motor 180 of the second drivesystem 202 such that the annular flange 238 supports the motor 180. Theannular flange 214 can also include one or more bores, which can providea mass savings. The throughbore 234 also receives a portion of the baseplate 224 to couple the body 220 to the base plate 224.

The flexible drive shaft 160 is substantially cylindrical, andinterconnects the interface 130 with the base plate 224. The flexibledrive shaft 160 is generally composed of a plurality of metal or metalalloy wires, which are wrapped in layers to define a substantiallycylindrical shaft. The flexible drive shaft 160 includes a first end 240and a second end 242. The first end 240 is coupled to the second post154 of the joint 150, and the second end 242 is coupled to the shaftcoupling 222. In one example, the first end 240 and the second end 242are coupled to the respective one of the second post 154 and the shaftcoupling 222 via bonding with an adhesive, however, welding, mechanicalfasteners, etc. can also be employed. The flexible drive shaft 160enables the rotation of the first articulation cylinder 134 relative tothe second articulation cylinder 200 in pitch (Y-axis) and roll(X-axis), while preventing motion in yaw (Z-axis). Stated another way,the flexible drive shaft 160 enables the rotation of the firstarticulation cylinder 134 relative to the second articulation cylinder200 in pitch (Y-axis) and roll (X-axis), while isolating the interface130 from any motion in yaw (Z-axis) and allowing the motion in pitch(Y-axis) and roll (X-axis).

The shaft coupling 222 is coupled to the second end 242 of the flexibledrive shaft 160. In this example, the shaft coupling 222 includes acylindrical body 244 and a circular flange 246. The shaft coupling 222is composed of metal or metal alloy, and in one example, is composed ofaluminum. The shaft coupling 222 can be formed through any suitabletechnique, such as, but not limited to, casting, molding, stamping,forging, selective laser sintering, etc. The cylindrical body 244defines a bore 248, which receives the second end 242 of the flexibledrive shaft 160. The flange 246 extends outwardly from the cylindricalbody 244 and assists with coupling the shaft coupling 222 to the baseplate 224.

The base plate 224 is coupled to the body 220 and to the vehicle 10. Thebase plate 224 is generally cylindrical and is composed of a metal ormetal alloy, including, but not limited to, aluminum. The base plate 224can be formed through any suitable technique, such as, but not limitedto, casting, molding, stamping, forging, selective laser sintering, etc.The base plate 224 includes a first base side 250, a second base side252 and can include one or more bores 254 defined through the first baseside 250 and the second base side 252 that cooperate with the one ormore bores of the body 220 to removably couple the body 220 to the baseplate 224. The first base side 250 is coupled to the sixth surface 232of the body 220, and in one example, the sixth surface 232 can also bebonded via an adhesive to the first base side 250 to further secure thebody 220 to the base plate 224. The first base side 250 defines anannular lip 256, which is received within a portion of the throughbore234 to assist in coupling the body 220 to the base plate 224. The firstbase side 250 also defines a receiving bore 258, which receives theshaft coupling 222 to couple the shaft coupling 222 to the base plate224. The shaft coupling 222 can be press-fit into the receiving bore258, or coupled to the receiving bore 258 via an adhesive, mechanicalfastener, etc.

The second base side 252 is coupled to the vehicle 10. The second baseside 252 may include one or more mounting features such as one or morebores 260, which receive a mechanical fastener, including, but notlimited to a bolt, screw, etc., to assist in fixedly, but removably,coupling the sensor platform system 100 to the vehicle 10. It should benoted that the sensor platform system 100 can be coupled to the vehicle10 at any desired location, and moreover, the sensor platform system 100can be coupled to or mounted on a support coupled to the vehicle 10, ifdesired, as illustrated in FIG. 1A.

With reference to FIGS. 3-8, in order to assemble the sensor platformsystem 100, in one example, with the joint 150 coupled to the interface130, the bearing 132 is coupled about the second side 142 of theinterface 130. The flexible drive shaft 160 is coupled to the secondpost 154 of the joint 150, and the first articulation cylinder 134 iscoupled about the bearing 132. The engagement portion 196 of the drivering 184 of the first drive system 136 is coupled to the firstarticulation cylinder 134 at the second counterbore 178, and the spindle182 is coupled to the rotor 180 a of the motor 180. The drive systembearing 188 is coupled about the base portion 194 of the drive ring 184,and the portion of the first drive system 136 is positioned within thesecond articulation cylinder 200 such that the drive system bearing 188is coupled to the third counterbore 210. The position sensor 186 iscoupled to the spindle 182.

The engagement portion 196 of the drive ring 184 of the second drivesystem 202 is coupled to the second articulation cylinder 200 at thefourth counterbore 212, and the spindle 182 is coupled to the rotor 180a of the motor 180 of the second drive system 202. The drive systembearing 188 is coupled about the base portion 194 of the drive ring 184and the portion of the second drive system 202 is positioned within thebody 220 such that the drive system bearing 188 is coupled to the fifthcounterbore 236. The position sensor 186 is coupled to the spindle 182of the second drive system 202. The shaft coupling 222 is coupled to theflexible drive shaft 160, and the shaft coupling 222 is coupled to thebase plate 224 such that the flexible drive shaft 160 interconnects theinterface 130 with the base plate 224. The base plate 224 is coupled tothe body 220. The sensor mount 108 is coupled to the interface 130, andthe sensing device 102 can be coupled to the sensor mount 108. With thesensor platform system 100 assembled, the sensor platform system 100 canbe coupled to the vehicle 10.

Generally, the sensor platform system 100 is coupled to the vehicle 10such that each of the motors 180 and the position sensors 186 are incommunication with the control module 18. Each of the motors 180 areresponsive to one or more control signals to rotate a respective one ofthe first articulation cylinder 134 about the axis of rotation R and thesecond articulation cylinder 200 about the axis of rotation R3. As theaxis of rotation R is angularly offset from or transverse to the axis ofrotation R3, the relative rotation between the first articulationcylinder 134 and the second articulation cylinder 200 results in the twodegrees of freedom for the motion of the sensor platform system 100,without obstructing a field of view of the sensing device 102 coupled tothe sensor mount 108. Further, as each of the first articulationcylinder 134 and the second articulation cylinder 200 are directlydriven by a respective spindle 182 and drive ring 184, the respectiveposition sensor 186 provides direct feedback as to the position of thefirst articulation cylinder 134 and the second articulation cylinder200, which results in improved accuracy in the determination of aposition for the sensor platform system 100. Moreover, as the sensormount 108, the interface 130 and the base plate 224 are interconnectedvia the flexible drive shaft 160, the sensor platform system 100 isconstrained in yaw (Z-axis) such that movement in yaw (Z-axis) isminimized or eliminated.

In one embodiment, the sensing device 102 comprises a lidar sensor,which in this example, has the shape of a beacon. It will be understood,however, that the sensing device 102 may include any suitable sensingdevice for use with the vehicle 10, including, but not limited to aradar sensor, an image sensor, etc. The sensing device 102 observesconditions associated with an environment about the vehicle 10, andgenerates sensor signals based thereon. The sensing device 102communicates these sensor signals over a suitable architecture thatfacilitates the transfer of data, commands, power, control signals, etc.to the control module 18. In various embodiments, the sensing device 102may be in wireless or wired communication with the control module 18.

The control module 18 outputs one or more control signals to the motor180 of the first drive system 136 and the second drive system 202 basedon inputs received from other modules of the vehicle 10 and based on thecontrol systems and methods of the present disclosure. In variousembodiments, the control module 18 outputs one or more first controlsignals to the motor 180 of the first drive system 136 and outputs oneor more second control signals to the motor 180 of the second drivesystem 202 based on the sensor signals from the position sensors 186,inputs received from other modules of the vehicle 10 and based on thecontrol systems and methods of the present disclosure.

Referring now to FIG. 9, and with continued reference to FIGS. 2-8, adataflow diagram illustrates various embodiments of a control system 300for the sensor platform system 100, which may be embedded within thecontrol module 18. Various embodiments of the control system 300according to the present disclosure can include any number ofsub-modules embedded within the control module 18. As can beappreciated, the sub-modules shown in FIG. 9 can be combined and/orfurther partitioned to similarly control the motor 180 of the firstdrive system 136 and the motor 180 of the second drive system 202.Inputs to the control system 300 may be received from the positionsensors 186 (FIG. 3), received from other control modules (not shown)associated with the vehicle 10, and/or determined/modeled by othersub-modules (not shown) within the control module 18. In variousembodiments, the control module 18 includes a position determinationmodule 302 and a movement control module 304.

The position determination module 302 receives as input desired positiondata 306. The desired position data 306 includes a desired orientationof the sensor platform system 100 in, for example, sphericalcoordinates. Generally, the desired position data 306 is received in theform of two angular coordinates theta (θ), phi(φ). In one example, thedesired position data 306 is received from other modules associated withthe vehicle 10, for example, based on a desired orientation for a fieldof view associated with the sensing device 102.

Based on the received desired position data 306, the positiondetermination module 302 calculates angles θ₁ and θ₂ to achieve thedesired orientation for the sensor platform system 100, while optimizingfor a smallest amount of rotation. Generally, the position determinationmodule 302 determines any pitch and roll combination of a top plane byrotating a top plane and a bottom plane with respect to each other.Stated another way, the position determination module 302 determines anypitch and roll actuated combination of a top plane by rotatingrespectively the first articulation cylinder 134 and the secondarticulation cylinder 200.

For example, with reference to FIG. 10, a neutral orientation for thesensor platform system 100 is shown. The orientation of a top plane ofthe sensor platform system 100 is defined by a unit vector V₁, which isorthogonal to the top plane of the sensor mount 108 of the sensorplatform system 100. The movement of the first articulation cylinder 134about the axis of rotation R is treated as a vector rotation about anS-axis, and the movement of the second articulation cylinder 200 aboutthe axis of rotation R3 is treated as a vector rotation about theZ-axis.

By projecting the vector V₁ onto the Y-Z plane, as vector V₁ rotatesabout the S-axis, the projection forms an angle θ_(s) between the Z-axisand the vector V₁ that is between 0 and θ_(s). This angle θ_(s) is halfof the maximum phi (φ) that can be input to the sensor platform system100. This rotation combined with the rotation about the Z-axis providesthe full range of motion for the sensor platform system 100. Statedanother way, the movement of the sensor platform system 100 isconstrained by (theta (θ), phi(φ)), where theta (θ) can be any numberand phi(φ) is based on the following equation:

φ≦2(θ_(s))  (1)

Based on the theta (θ), phi(φ) received from the desired position data306, the position determination module 302 determines θ_(s) usingequation (1) and solves the following equation to calculate angle θ₂:

θ₂=2πn+arccos(cot(−θ_(s))tan(φ−θ_(s)))  (2)

The position determination module 302 solves equation (2) based on thefollowing conditions:

$\begin{matrix}{{{\tan \left( \theta_{s} \right)} \neq 0};} & (3) \\{{{{- \frac{1}{2}}\left( {{{- 2}\theta_{s}} - \pi} \right)} < \phi < {\frac{1}{2}\left( {\pi - {2\theta_{s}}} \right)}};{and}} & (4) \\{n \in Z} & (5)\end{matrix}$

Wherein θ₂ is an angle of rotation for the first articulation cylinder134 about the axis of rotation R, and n is an integer. For example,based on an input phi(φ) of about 15 degrees, θ₂ is about 180 degrees,which results in a rotation of the first articulation cylinder 134 180degrees from the neutral position shown in FIG. 10. Generally, therelationship between phi(φ) and angle θ₂ is non-linear. Based on thecalculation of angle θ₂, the position determination module 302 solvesthe following equation to calculate angle θ₁:

θ₁=θ−θ₂  (6)

Wherein θ₁ is an angle of rotation for the second articulation cylinder200 about the axis of rotation R3.

Generally, angle θ₁ and angle θ₂ comprise absolute positions for thespindle 182 of the second drive system 202 about the axis of rotation R3and the spindle 182 of the first drive system 136 about the axis ofrotation R, respectively. The position determination module 302 setsangle θ₁ 308 and sets angle θ₂ 310 for the movement control module 304.

Based on angle θ₁ 308, the movement control module 304 outputs one ormore control signals 312 for the motor 180 of the second drive system202 to move the spindle 182, and thus, the second articulation cylinder200, about the axis of rotation R3 to the position of angle θ₁. Invarious embodiments, the movement control module 304 can convert thereceived angle θ₁ 308 into the one or more control signals 312 for themotor 180. In various embodiments, the movement control module 304 canconvert the received angle θ₁ 308 based on a table stored in memory,such as the memory 24.

In various embodiments, the movement control module 304 also receives asinput first sensor data 314. The first sensor data 314 includes thesensor signals received from the position sensor 186 of the second drivesystem 202, which provides feedback as to the measured position of themotor 180 of the second drive system 202. Based on the first sensor data314, in one example, the movement control module 304 determines aposition of the second articulation cylinder 200. In variousembodiments, the movement control module 304 also determines whether themotor 180 of the second drive system 202 is in the orientation of angleθ₁ 308. In various embodiments, the movement control module 304 canoutput an error signal based a difference in the measured position ofthe motor 180 of the second drive system 202, and the orientation of themotor 180 based on the one or more control signals 312. In addition, thefirst sensor data 314 can be received as input to other modulesassociated with the vehicle 10.

Based on angle θ₂ 310, the movement control module 304 outputs one ormore control signals 316 for the motor 180 of the first drive system 136to move the spindle 182, and thus, the first articulation cylinder 134about the axis of rotation R to the position of angle θ₂. In variousembodiments, the movement control module 304 can convert the receivedangle θ₂ 310 into the one or more control signals 316 for the motor 180.In various embodiments, the movement control module 304 can convert thereceived angle θ₂ 310 based on a table stored in memory, such as thememory 24.

In various embodiments, the movement control module 304 also receives asinput second sensor data 318. The second sensor data 318 includes thesensor signals received from the position sensor 186 of the first drivesystem 136, which provides feedback as to the measured position of themotor 180 of the first drive system 136. Based on the second sensor data318, in one example, the movement control module 304 determines aposition of the first articulation cylinder 134. In various embodiments,the movement control module 304 also determines whether the motor 180 ofthe first drive system 136 is in the orientation of angle θ₂ 310. Invarious embodiments, the movement control module 304 can output an errorsignal based a difference in the measured position of the motor 180 offirst drive system 136, and the orientation of the motor 180 based onthe one or more control signals 316. In addition, the second sensor data318 can be received as input to other modules associated with thevehicle 10. In addition, in various embodiments, the movement controlmodule 304 can determine a position of the sensor platform system 100based on the determined position of the first articulation cylinder 134and the second articulation cylinder 200, which can be output to othermodules associated with the vehicle 10.

Referring now to FIG. 11, and with continued reference to FIGS. 1A-10, aflowchart illustrates a control method 400 that can be performed by thecontrol module 18 of FIG. 1B in accordance with the present disclosure.As can be appreciated in light of the disclosure, the order of operationwithin the method is not limited to the sequential execution asillustrated in FIG. 11, but may be performed in one or more varyingorders as applicable and in accordance with the present disclosure.

In various embodiments, the method can be scheduled to run based onpredetermined events, and/or can run based on the receipt of desiredposition data 306.

The method begins at 402. At 404, the method receives as input thedesired position data 306. At 406, based on the desired position data306, the method calculates angle θ₂ with equations (1)-(5) discussedherein above at 406 a, and also calculates angle θ₁ with equation (6) at406 b. At 408, the method outputs one or more control signals 312 forthe motor 180 of the second drive system 202 to move the secondarticulation cylinder 200 based on the calculated angle θ₁ at 408 a, andoutputs one or more control signals 316 for the motor 180 of the firstdrive system 136 to move the first articulation cylinder 134 based onthe calculated angle θ₂ at 408 b. The method ends at 410.

It should be noted that while the method is illustrated herein asoutputting the one or more control signals 312 and the one or morecontrol signals 316 substantially simultaneously to result insynchronous movement of the sensor platform system 100, the method isnot so limited. In this regard, the method can output the one or morecontrol signals 312 for the first drive system 136 at a first timeinterval, and can output the one or more control signals 316 for thesecond drive system 202 at a second time interval such that the sensorplatform system 100 moves in an asynchronous manner.

It should be noted that the various teachings of the present disclosureare not limited to sensor platform systems that include two articulationsystems. Rather, with reference to FIG. 12, a sensor platform system 100a for use with the sensor system 12 of the vehicle 10 (FIG. 1B) isshown. As the sensor platform system 100 a can be substantially similarto the sensor platform system 100, the same reference numerals will beused to denote the same or substantially similar components. In thisexample, the sensor platform system 100 a includes the sensor mount 108for coupling the sensing device 102 (FIG. 1A) to the sensor platformsystem 100 a, a plurality of the first articulation systems 110 a-110 n,a plurality of the second articulation systems 112 a-112 n and the baseplate 224. In this example, with reference to FIG. 13, the sensorplatform system 100 a does not include the body 220 or the flexibledrive shaft 160 such that the sensor platform system 100 a acts as anarticulating arm. Stated another way, by removing the flexible driveshaft 160, the sensor platform system 100 a is movable in yaw (e.g.rotation about the Z-axis), pitch (e.g., rotation about the Y-axis) androll (e.g., rotation about the X-axis) to define a platform for thesensing device 102 with three degrees of rotational freedom.

The sensor platform system 100 a is shown to include a plurality of thefirst articulation systems 110 a-110 n and a plurality of the secondarticulation systems 112 a-112 n. In this example, the plurality of thefirst articulation systems 110 a-110 n are coupled to the plurality ofthe second articulation systems 112 a-112 n in an alternating patternfrom the base plate 224 (e.g. the second articulation system 112 a, thefirst articulation system 110 a, the second articulation system 112 b,the first articulation system 110 b and so on) to define three degreesof rotational freedom for positioning the sensor platform 100 a.Generally, the sensor platform system 100 a is coupled together suchthat the slanted second surface 172 of a respective first articulationcylinder 134 is coupled or adjacent to the slanted third surface 204 ofa respective second articulation cylinder 200, and the first surface 170of a respective first articulation cylinder 134 is adjacent to thefourth surface 206 of a respective second articulation cylinder 200. Thecoupling of the respective slanted second surface 172 and the respectiveslanted third surface 204 enables the relative movement between therespective one of the plurality of first articulation systems 110 a-110n and the respective one of the plurality of second articulation systems112 a-112 n. In this example, a respective one of the first articulationsystems 110 a-110 n is received at least partially within a respectiveone of the second articulation systems 112 a-112 n. While the sensorplatform system 100 a is illustrated herein as including three of thefirst articulation systems 110 and three of the second articulationsystems 112, it will be understood that the sensor platform system 100 acan include any number of the first articulation system 110 and thesecond articulation system 112. In this example, the first articulationsystem 110 n does not include the universal joint on the interface 130 nas the sensor platform system 100 a does not include the flexible driveshaft 160.

Moreover, while the interface 130 n of the first articulation system 110n includes the first side 140 with the plurality of projections 144, theinterfaces 130 a, 130 b associated with each of the first articulationsystems 110 a, 110 b need not include the plurality of projections 144about the first side 140 of the interface 130 a, 130 b. Rather, thefirst side 140 of the interface 130 a, 130 b of each of the firstarticulation systems 110 a, 110 b is substantially annular so as to bereceived within the fourth counterbore 212 of the respective one of thesecond articulation cylinder 200 b, 200 n.

As the sensor platform system 100 a is movable by the control module 18in the same or similar way as the sensor platform system 100, themovement of the sensor platform system 100 a will not be discussed ingreat detail herein. Briefly, however, with the sensor platform system100 a assembled, the motor 180 associated with the first drive system136 is responsive to one or more control signals received from thecontrol module 18 to rotate the first articulation cylinder 134 a aboutthe longitudinal axis L. The motor 180 associated with the second drivesystem 202 is responsive to one or more control signals received fromthe control module 18 to rotate the second articulation cylinder 200 babout the longitudinal axis L relative to the first articulationcylinder 134 a and the first articulation cylinder 134 b. The motor 180associated with the first drive system 136 is responsive to one or morecontrol signals received from the control module 18 to rotate the firstarticulation cylinder 134 b about the longitudinal axis L relative tothe second articulation cylinder 200 b and the second articulationcylinder 200 n. The motor 180 associated with the second drive system202 is responsive to one or more control signals received from thecontrol module 18 to rotate the second articulation cylinder 200 n aboutthe longitudinal axis L relative to the first articulation cylinder 134n and the first articulation cylinder 134 b. The motor 180 associatedwith the first drive system 136 is responsive to one or more controlsignals received from the control module 18 to rotate the firstarticulation cylinder 134 n about the longitudinal axis L relative tothe second articulation cylinder 200 n. The rotation of the firstarticulation cylinder 134 n results in a direct rotation of the sensormount 108 coupled to the first articulation system 110 n. Thus, each ofthe first articulation systems 110 a-110 n and each of the secondarticulation systems 112 a-112 n are independently movable upon receiptof one or more control signals from the control module 18.

Generally, the sensor platform system 100 a is in communication with thecontrol module 18 over a suitable architecture that facilitates thetransfer of commands, data, power, control signals, etc., such as a bus.Each of the motors 180 associated with the respective ones of theplurality of the first articulation systems 110 a-110 n and theplurality of second articulation systems 112 b-112 n are incommunication with the control module 18, over a suitable architecturethat facilitates the transfer of commands, data, power, control signals,etc., and are responsive to one or more control signals received fromthe control module 18 to rotate the respective motor 180 about thelongitudinal axis L. Each of the position sensors 186 associated withthe respective ones of the plurality of the first articulation systems110 a-110 n and the plurality of second articulation systems 112 b-112 nare in communication with the control module 18 over a suitablearchitecture that facilitates the transfer of commands, data, power,control signals, etc., to communicate sensor signals generated based onthe observed position of the respective spindle 182 to the controlmodule 18.

The control system for the sensor platform system 100 a, which may beembedded within the control module 18, is similar to the control system300 for the sensor platform system 100. Generally, the control systemfor the sensor platform system 100 a controls the motor 180 of the firstdrive system 136 of the plurality of the first articulation systems 110a-110 n and controls the motor 180 of the second drive system 202 of theplurality of second articulation systems 112 a-112 n. In this example,the position determination module receives as input the desired positiondata, which includes a desired orientation of the sensor platform system100 a in, for example, spherical coordinates. Based on the receiveddesired position data and the percent slant of the respective slantedsecond surfaces and the slanted third surfaces, the number of firstarticulation systems 110 a-110 n and the number of second articulationsystems 112 a-112 n, the position determination module calculates anglesθ₁, θ₂, to achieve the desired orientation for the sensor platformsystem 100 a, while optimizing for a smallest amount of rotation. Basedon the computed angle θ₁, the movement control module outputs one ormore control signals for the motor 180 of the second drive system 202 tomove the spindle 182, and thus, the respective second articulationcylinder 200 b to the orientation of angle θ₁ Based on the computedangle θ₂, the movement control module outputs one or more controlsignals for the motor 180 of the first drive system 136 to move thespindle 182, and thus, the respective first articulation cylinder 134 ato the orientation of angle θ₂. This process is repeated for each of thecomputed angles for each of the first drive systems 136 and the seconddrive systems 202 until the sensor platform system 100 a is in thedesired orientation.

While at least one exemplary embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexemplary embodiment or exemplary embodiments are only examples, and arenot intended to limit the scope, applicability, or configuration of thedisclosure in any way. Rather, the foregoing detailed description willprovide those skilled in the art with a convenient road map forimplementing the exemplary embodiment or exemplary embodiments. Itshould be understood that various changes can be made in the functionand arrangement of elements without departing from the scope of thedisclosure as set forth in the appended claims and the legal equivalentsthereof.

What is claimed is:
 1. A sensor platform, comprising: a sensor mountadapted to receive a sensing device; a first articulation system thathas a first rotational axis; a second articulation system that has asecond rotational axis, the second rotational axis different than thefirst rotational axis; and a base that supports the first articulationsystem, the second articulation system and the sensor mount, wherein thefirst articulation system and the second articulation system areindependently movable to define two degrees of freedom for positioningthe sensor platform.
 2. The sensor platform of claim 1, wherein thefirst articulation system includes a first articulation body that ismovable by a first drive system and the second articulation systemincludes a second articulation body that is movable by a second drivesystem.
 3. The sensor platform of claim 2, wherein a portion of thefirst drive system is received within the second articulation body and aportion of the second drive system is received within the base.
 4. Thesensor platform of claim 2, wherein the first articulation body and thesecond articulation body are cylinders that include a slanted surface,and the slanted surface of the first articulation body is positionedadjacent to the slanted surface of the second articulation body.
 5. Thesensor platform of claim 1, wherein the first rotational axis isangularly offset with respect to the second rotational axis.
 6. Thesensor platform of claim 1, wherein the sensor mount is coupled to thefirst articulation system, and the base is coupled to the secondarticulation system.
 7. The sensor platform of claim 1, furthercomprising a flexible drive shaft that is coupled to the sensor mountand the base, and the flexible drive shaft inhibits motion in a thirddegree of freedom.
 8. The sensor platform of claim 2, wherein the firstdrive system and the second drive system each include motors thatdirectly drive spindles coupled to the respective one of the firstarticulation body and the second articulation body.
 9. The sensorplatform of claim 1, further comprising the sensing device, and the baseof the sensor platform is coupled to a vehicle.
 10. A sensor platform,comprising: a first articulation system that has a first rotationalaxis; a second articulation system that has a second rotational axis,the first rotational axis angularly offset from the second rotationalaxis, the first articulation system coupled to the second articulationsystem such that the first articulation system and the secondarticulation system extend along a longitudinal axis; and wherein thefirst articulation system and the second articulation system areindependently movable to define two degrees of rotational freedom forpositioning the sensor platform.
 11. The sensor platform of claim 10,wherein the first rotational axis is transverse to the longitudinal axisand the second rotational axis is substantially parallel to thelongitudinal axis.
 12. The sensor platform of claim 10, wherein thesensor platform comprises a plurality of the first articulation systemsand a plurality of the second articulation systems, which are coupledtogether to define three degrees of rotational freedom for positioningthe sensor platform.
 13. The sensor platform of claim 10, furthercomprising a sensor mount adapted to receive a sensing device, thesensor mount coupled to the first articulation system.
 14. The sensorplatform of claim 10, further comprising a base that supports the firstarticulation system and the second articulation system, and the base iscoupled to an autonomous vehicle.
 15. The sensor platform of claim 10,wherein the first articulation system includes a first articulation bodythat is movable by a first drive system and the second articulationsystem includes a second articulation body that is movable by a seconddrive system.
 16. An autonomous vehicle, comprising: a sensing devicethat observes a condition associated with the autonomous vehicle; and asensor platform coupled to the sensing device and the vehicle, thesensing device including a first articulation system that is movableabout a first rotational axis and a second articulation system that ismovable about a second rotational axis, the first rotational axisdifferent than the second rotational axis, and the first articulationsystem and the second articulation system define two degrees ofrotational freedom for positioning the sensor platform, the sensorplatform extending along a longitudinal axis.
 17. The autonomous vehicleof claim 16, wherein the first articulation system includes a firstarticulation body that is movable by a first drive system, the secondarticulation system includes a second articulation body that is movableby a second drive system.
 18. The autonomous vehicle of claim 17,wherein the first articulation body and the second articulation body arecylinders that include a slanted surface, and the slanted surface of thefirst articulation body is positioned adjacent to the slanted surface ofthe second articulation body.
 19. The autonomous vehicle of claim 16,wherein the first rotational axis is transverse to the longitudinal axisand the second rotational axis is substantially parallel to thelongitudinal axis.
 20. The autonomous vehicle of claim 16, wherein thesensor platform further comprises a plurality of the first articulationsystems and a plurality of the second articulation systems, with aportion of at least one of the plurality of the first articulationsystems received within a respective one of the plurality of the secondarticulation systems.